Using Watershed Scale Geomorphic Assessment to Improve Urban Stream Restoration Design

Catchment urbanization is widely recognised as a primary driver of stream degradation by increasing stormwater runoff causing major changes to key ecosystem processes. Reinstating the ‘natural’ hydrogeomorphic conditions is central in designing successful, self-sustaining restoration actions. However, addressing urban stream degradation by re-establishing the hydrogeomorphic conditions remains a challenge and comparatively limited measurable progress has been observed particularly achieving ecological objectives. This paper articulates that stream restoration goals might be better achieved when management measures take a broader approach that considers anticipated hydraulic conditions effects that liaise relationships between flow and ecology. The study argues that fluvial systems are characterised by complex and dynamic ecosystem processes primarily governed by the hydraulic conditions (e.g. velocity, depth, shear stress), thus, as the practice of addressing urban stream restoration becomes increasingly common, it is critical to explore and understand the anticipated response of the hydraulic conditions. This paper describes how hydraulic regime consideration provides further opportunity for a holistic approach to urban stream management given their capacity to account for multiple ecological and geomorphic objectives. The paper suggests that developing suitable flow-biota-ecosystem processes nexus is critical towards addressing urban stream degradation and hydraulic consideration in restoration actions provide an important step towards that. The paper discusses opportunities to evolve management actions to achieve restoration goals by highlighting how the management of the two key levers (addressing altered flow regime and morphology) to improve the hydraulic conditions can help to address the urban stream disturbance.

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Chapter 7. Urban Stream Restoration: Recovering Ecological Services in Degraded Watersheds

Growing Greener Cities ◽

10.9783/9780812204094.127 ◽

2008 ◽

pp. 127-151 ◽

Cited By ~ 2

Keyword(s):

Stream Restoration ◽

Urban Stream ◽

Ecological Services

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Flood Flow Frequency Analysis to Estimate Potential Floodplain Nitrogen Treatment during Overbank Flow Events in Urban Stream Restoration Projects

Water ◽

10.3390/w12061568 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1568

Author(s):

Barbara A. Doll ◽

J. Jack Kurki-Fox ◽

Jonathan L. Page ◽

Natalie G. Nelson ◽

Jeffrey P. Johnson

Keyword(s):

North Carolina ◽

Chesapeake Bay ◽

Stream Restoration ◽

Nitrogen Retention ◽

Quality Data ◽

Urban Stream ◽

Water Quality Data ◽

Total N ◽

North Carolina Department ◽

Overbank Flow

Stream restoration for mitigation purposes has grown rapidly since the 1980s. As the science advances, some organizations (Chesapeake Bay Program, North Carolina Department of Environmental Quality) have approved or are considering providing nutrient credits for stream restoration projects. Nutrient treatment on floodplains during overbank events is one of the least understood processes that have been considered as part of the Chesapeake Bay Program’s Stream Restoration Nutrient Crediting program. This study analyzed ten years of streamflow and water quality data from five stations in the Piedmont of North Carolina to evaluate proposed procedures for estimating nitrogen removal on the floodplain during overbank flow events. The volume of floodplain flow, the volume of floodplain flow potentially treated, and the nitrogen load retained on the floodplain were calculated for each overbank event, and a sensitivity analysis was completed. On average, 9% to 15% of the total annual streamflow volume accessed the floodplain. The percentage of the average annual volume of streamflow potentially treated ranged from 1.0% to 5.1%. Annually, this equates to 0.2% to 1.0% of the total N load retained/removed on the floodplain following restoration. The relatively low nitrogen retention/removal rates were due to a majority of floodplain flow occurring during a few large events each year that exceeded the treatment capacity of the floodplain. On an annual basis, 90% of total floodplain flow occurred during half of all overbank events and 50% of total floodplain flow occurred during two to three events each year. Findings suggest that evaluating only overbank events may lead to undervaluing stream restoration because treatment is limited by hydrologic controls that restrict floodplain retention time. Treatment is further governed by floodplain and channel size.

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Assessing stream restoration potential of recreational enhancements on an urban stream, Springfield, Ohio

The Challenges of Dam Removal and River Restoration ◽

10.1130/2013.4121(11) ◽

2013 ◽

Cited By ~ 1

Author(s):

John Ritter ◽

Kelly Shaw ◽

Aaron Evelsizor ◽

Katherine Minter ◽

Chad Rigsby ◽

...

Keyword(s):

Stream Restoration ◽

Urban Stream ◽

Restoration Potential

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UAV Monitoring of Stream Restorations

Hydrology ◽

10.3390/hydrology6020029 ◽

2019 ◽

Vol 6 (2) ◽

pp. 29 ◽

Cited By ~ 4

Author(s):

Jakub Langhammer

Keyword(s):

Spatial Data ◽

Stream Restoration ◽

Riparian Zone ◽

Qualitative Assessment ◽

Urban Stream ◽

Stream Channel ◽

The Czech Republic ◽

Restoration Monitoring ◽

Unique Source

This study examines the potential and limits of the unmanned aerial vehicles (UAVs) applicability for the monitoring of stream restoration in an urban environment. UAV imaging was used for long-term post-restoration monitoring of an urban stream. The monitoring was aimed to track the stream changes significant for the assessment of the restoration success, such as the compliance of the restoration to the plan, stability and evolution of the stream channel, or changes in stream and riparian habitats. The recurrent imaging campaigns in the restored segment of Hostavicky brook in Prague, The Czech Republic, were undertaken for three years since the restoration using the DJI Inspire 1 Pro platform. The UAV monitoring revealed that the new stream pattern substantially differs from the proposed restoration plan. Despite this, the new channel has proved stability, supported by intense grassing of the floodplain, resulting in only marginal evolution of the restored channel. The new channel proved the ability to mitigate the course of a significant flood event without significant flood spills outside the riparian zone. The UAV monitoring also revealed intense eutrophication in newly created shallow ponds with insufficient drainage. The research proved that UAV imaging is a unique source of spatial data, providing reliable information for quantitative and qualitative assessment of the stream restoration progress and success.

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